Chapter 6 - Lipid - Comstock.pptx

Chapter 6 - Lipids Learning Objectives Recognize the basic chemical structure of fatty acids and describe how they are named. Explain the functions of triglycerides, fatty acids, phospholipids, and sterols in the body. Classify and evaluate the different fatty acids based on their he...

Chapter 6 - Lipids Learning Objectives Recognize the basic chemical structure of fatty acids and describe how they are named. Explain the functions of triglycerides, fatty acids, phospholipids, and sterols in the body. Classify and evaluate the different fatty acids based on their health benefits or consequences. Identify food sources of triglycerides, fatty acids, phospholipids, and sterols. Discuss the recommended intake of lipids. Identify strategies for modifying total fat, saturated fat, and trans fat intake. Summarize the digestion, absorption, and transport of lipids in the body. Explain the relationship of dietary lipids to chronic diseases. Describe dietary measures to reduce the risk of developing cardiovascular disease. 2 Chapter Outline Triglycerides Food Sources of Triglycerides Functions of Triglycerides Sterols Recommended Fat Intake Fat Digestion and Absorption Transporting Lipids in the Blood Health Concerns Related to Fat Intake 3 Introduction to Lipids (Fats and Oils) Many foods contain some fat Foods rich in lipid include: Vegetable oil, butter, margarine, avocado, nuts, seeds Meat, cheese, peanut butter, cakes, pies, cookies, muffins, chocolate, ice cream, chips Wide range of functions Add flavor and texture to food Provide energy Aid in the absorption and transport of fat-soluble vitamins (__, __, __, __) Insulate the body, preserve body heat, and protect organs Used to make certain hormones Take home message: Fats are essential for many body functions and not all fats exert the same impact on health! 4 Sources of Fat 5 Introduction to Lipids Contain carbon, hydrogen, and oxygen Do not dissolve in water Lipid family includes: Triglycerides, Phospholipids, and Sterols __________ are the most common type of lipid found in foods and in the body _____ Lipids that are solid at room temperature Examples include butter, lard, etc. _____ Lipids that are liquid at room temperature Examples include olive oil, canola oil, etc. Lipids contain 9 kcal/gram 4 grams of Lipid = __________ kcal 15 grams of Lipid = __________ kcal 62 grams of Lipid = __________ kcal 6 Triglycerides Triglycerides 3 Fatty Acids attached to a Glycerol “backbone” The fatty acids attached to glycerol can be the same or different Diglycerides 2 Fatty Acids attached to a Glycerol Triglyceride that has lost 1 Fatty Acid Monoglycerides 1 Fatty Acid attached to a Glycerol Triglyceride that has lost 2 Fatty Acids 7 Terms to Know Esterification – Adding fatty acids to a glycerol Ester bond – formed between a fatty acid and glycerol One molecule of H2O is released each time an ester bond is formed De-esterification – The release of fatty acids from glycerol Triglyceride  Diglyceride  Monoglyceride Re-esterification – Reattaching a fatty acid to glycerol Monoglyceride  Diglyceride  Triglyceride Hydrolysis is the reaction that releases fatty acids from glycerol Fatty acids released during this process are referred to as Free Fatty Acids 8 Free Fatty Acids All fatty acids have the same basic structure Long chains of carbon linked together and surrounded by hydrogen atoms Carboxyl group at one end, methyl group at the other Fatty acids vary in three ways: 1. Length – The # of carbons in the chain 2. Saturation – The extent to which the chain is saturated with Carboxyl Group hydrogen “Saturated” = No double bonds “Unsaturated” = One or more double bonds 3. Shape CH3 Methyl Group Straight chain vs. Bent chain Double bonds cause a bend 9 Fatty Acid Length Long-Chain Fatty Acids – 12+ carbons in length Sources: Beef, pork, lamb, fish, and most plant oils Take the longest to digest Transported via the lymphatic system Medium-Chain Fatty Acids – 6 to 10 carbons in length Sources: Coconut oil, palm oil, or palm kernel oil, dairy products Rapidly digested Transported via the portal system Short-Chain Fatty Acids – Less than 6 carbons in length Sources: Butter (small amount); fiber-containing foods SCFAs are created when probiotics in our gut ferment prebiotic fibers! Rapidly digested Transported via the portal system 10 Fatty Acid Saturation Saturated Fatty Acid (SFA) No double bonds Carbon atoms are fully “saturated” with hydrogen atoms Examples: Myristic, Palmitic, & Stearic Acid Monounsaturated Fatty Acid (MUFA) One double bond One location in the carbon chain is not saturated with hydrogen Example: Oleic acid Polyunsaturated Fatty Acid (PUFA) Two or more double bonds Examples: Linoleic Acid, Gamma-Linolenic Acid, ARA, Alpha-Linolenic Acid, EPA, DHA 11 Fatty Acid Shape Notice how the double bonds cause the fatty acid to 12 bend ______________ Fatty Acid ______________ Fatty Acid ______________ Fatty Acid 13 Hydrogenation Hydrogenation – The process of adding hydrogen to an unsaturated fat Fully Hydrogenated Oils – All double bonds are converted to single bonds Unsaturated fat becomes more saturated Liquid oil becomes more like a solid fat Partially Hydrogenated Oils – Some double bonds are converted to single bonds Trans fatty acids are formed In 2015, the FDA determined that partially hydrogenated oils (PHOs), the major source of artificial trans fat in the food supply, were no longer Generally Recognized as Safe (GRAS). By 2020, all PHOs were removed from foods. 14 Trans Fat Free…Or Was It? At one point in time, a food could be considered “Trans Fat Free” if it contained 0.5 grams or less of trans fat per serving. If a food had 0.49 grams of trans fat per serving, the manufacturer could legally list that it contained 0g of trans fat. Any time a food listed “Partially hydrogenated ________ oil” within the ingredient list, then it contained trans fat. Please Note: Fully Hydrogenated oils do not contain trans fats and are still found in foods. 15  How do the calories, cholesterol, sodium, vitamin Great Value Whole Milk A, calcium, and potassium compare between the whole milk on this slide and the 2% milk on the next slide? 16  How do the calories, cholesterol, sodium, vitamin Great Value 2% Milk A, calcium, and potassium compare between the whole milk and 2% milk? 17 Naming Fatty Acids Two systems are used Both based on the # of carbon atoms and the location of double bonds Omega (ω) System Methyl end (CH3) = omega end Indicates where the first double bond closest to the methyl end occurs Linoleic Acid: 18:2 ω6 Delta (Δ) System Describes fatty acids in relation to the carboxyl end (COOH) of the carbon chain Indicates the location of all double bonds Linoleic Acid: 18:2 Δ9, 12 18 Omega System – Linoleic Acid: 18:2 ω6 Carbon 1 Carbon 18 Carbon 6 Omega End Two Double Bonds 19 Delta System – Linoleic Acid: 18:2 Δ9, 12 Carbon Carbon 12 Carbon 1 18 Carbon 9 Delta Two Double End Bonds 20 Name This Fatty Acid Using the Omega Naming System Total carbons = __________ Number of carbon-carbon double bonds = __________ First double bond located at carbon __________ 22 Arachidonic Acid =___:___ ω___ Essential Fatty Acids (EFAs) Necessary for health, body cannot synthesize, must come from food Alpha-Linolenic Acid (ALA) (18:3 ω3) PUFA Used to make EPA and DHA and certain Eicosanoids Linoleic Acid (LA) (18:2 ω6) PUFA Used to make Dihomo-gamma-linolenic acid and Arachidonic acid (ARA) and certain Eicosanoids 23 24 Eicosanoids Hormone-like compounds Play role in: Blood pressure regulation Blood clotting Sleep/wake cycles Body temperature regulation Inflammatory reactions Hypersensitivity reactions Regulation of cell division Maintaining normal kidney function and fluid balance In general: Eicosanoids formed from Omega-3s = Anti-inflammatory effects Eicosanoids formed from Omega-6s = Pro-inflammatory effects 25 Sources of Omega-3 Fatty Acids Alpha-Linolenic Acid (ALA) – Nuts, seeds, plant oils Flaxseed and Flaxseed Oil Chia Seeds Walnuts and Walnut Oil Canola Oil Soy-Based Foods (Soymilk, tofu, edamame, etc.) and Soybean Oil Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) – Fish and seafood Herring Salmon Mackerel Sardines Rainbow Trout Tuna Oysters Crab Omega-3 Supplements (fish oil, krill oil, cod liver oil, and algal oil ) Read more here: https://lpi.oregonstate.edu/mic/other-nutrients/essential-fatty-acids#sources 26 FYI: USDA Nutrient Databases for Omega-3s Sources of ALA, listed by Amount – https://ods.od.nih.gov/pubs/usdandb/ALA-Content.pdf Which food is listed at the top of this list? Sources of EPA, listed by Amount – https://ods.od.nih.gov/pubs/usdandb/EPA-Content.pdf What are the top three foods listed? Sources of DHA, listed by Amount – https://ods.od.nih.gov/pubs/usdandb/DHA-Content.pdf What are the top two foods listed? 27 EPA and DHA Eicosapentaenoic Acid (EPA) (20:5 ω3) Omega-3 PUFA Synthesized from Alpha-Linolenic Acid (ALA) or obtained directly from the diet ALA  Eicosapentaenoic acid (EPA) Needed for proper fetal development and healthy aging Docosahexaenoic Acid (DHA) (22:6 ω3) Omega-3 PUFA Synthesized from EPA or obtained directly from the diet ALA  Eicosapentaenoic acid (EPA)  Docosahexaenoic acid (DHA) Supports brain and eye development and function 28 DHA Optimal intake of DHA is especially essential for pregnant and nursing mothers to ensure adequate brain development in their children. DHA is essential for the adult brain because it impacts the brain’s structure and signaling systems and promotes nervous system development and optimal memory function. Deficiency has been linked with psychiatric disorders including depression, suicidal behavior, anger, and hostility. 29 Additional Benefits of Omega-3 Fatty Acids Observational studies link higher intakes of fish, seafood, and omega-3s with improved health outcomes May reduce the risk of certain cancers, including breast and colorectal cancer May reduce joint swelling in autoimmune diseases like rheumatoid arthritis https://pubmed.ncbi.nlm.nih.gov/28302406/ May reduce cardiovascular disease risk May reduce eye disease risk May prevent or slow cognitive deterioration Supports reproductive health May improve mental health Getting adequate amounts of DHA and EPA may be associated with a reduced risk of depression 30 Essential Fatty Acid Deficiency Clinical signs include: Dry scaly rash Decreased growth in infants and children Increased susceptibility to infection Poor wound healing FYI: If interested, you can learn more about omega-3s here: https://ods.od.nih.gov/factsheets/Omega3FattyAcids-HealthProfessional/ https://ods.od.nih.gov/factsheets/Omega3FattyAcids-Consumer/ https://lpi.oregonstate.edu/mic/other-nutrients/essential-fatty-acids https://medlineplus.gov/druginfo/meds/a607065.html 31 Sources of Fat Saturated Fat Butter, ghee, and lard Coconut oil, palm oil, and palm kernel oil Red meat – Beef, pork, lamb Dairy – Milk, ice cream, sour cream, cheese, etc. Baked goods and ultra-processed foods Monounsaturated Fat Olive oil, canola oil, peanut oil, avocado oil Olives, avocados Nuts, seeds, and nut butters – Macadamia nuts, hazelnuts, almonds, pecans, peanuts, almond butter, peanut butter Polyunsaturated Fat Plant oils – Safflower oil, sunflower oil, corn oil, soybean oil Walnuts, flax oil, flax seeds, chia seeds Fish, seafood, fish oil Trans Fat Found naturally in milk and dairy Partially hydrogenated oils, fast food, fried food 32  Americans consume a lot of saturated fat Saturated fat can raise LDL (“bad”) cholesterol levels Saturated Fat AHA: Limit saturated fat intake to 5% to 6% of total daily calories. DGAs: Limit saturated fat intake to 10% of total daily calories. 33  Monounsaturated fat can lower LDL (“bad”) cholesterol levels Monounsaturated AHA: Consume foods that contain monounsaturated fats in place Fat of those that contain saturated fats and/or trans fats. 34  Polyunsaturated fat can lower LDL (“bad”) cholesterol levels Polyunsaturated AHA: Consume foods that contain polyunsaturated fats in place Fat of those that contain saturated fats and/or trans fats. 35 Simple Swaps to Reduce Your Saturated Fat Intake… 70% Ground Beef 80% Ground Beef 90% Ground Beef (100 g) (100 g) (100 g) Calories: 332 kcal Calories: 243 kcal Calories: 185 kcal Total Fat: 30 g Total Fat: 19.4 g Total Fat: 12.8 g Protein: 14.4 g Protein: 17.5 g Protein: 18.2 g https://fdc.nal.usda.gov/f https://fdc.nal.usda.gov/f https://fdc.nal.usda.gov/ dc-app.html#/food-detail dc-app.html#/food-detail fdc-app.html#/food- s/168652/nutrients s/2514744/nutrients details/2514743/ nutrients Fewer kcal and less saturated fat 36 Less Healthy Options… Bacon (100 g) Hot Dog (100 g) Sausage (100 g) Calories: 468 kcal Calories: 310 kcal Calories: 309 kcal Total Fat: 35.1 g Total Fat: 28 g Total Fat: 28.2 g Protein: 33.9 g Protein: 11.7 g Protein: 12 g Percent of Calories from Percent of Calories from Percent of Calories from Fat: 67.5% Fat: 81.3% Fat: 82.1% https://fdc.nal.usda.gov/fdc-a https://fdc.nal.usda.gov/fdc-a https://fdc.nal.usda.gov/fdc- pp.html#/food-details/16832 pp.html#/food-details/32312 app.html#/food-details/ 2/nutrients 1/nutrients 174584/nutrients 37 Vs. Healthier Options… Chicken Breast (100 g) Shrimp (100 g) Canned Tuna (100 g) Calories: 158 kcal Calories: 99 kcal Calories: 128 kcal Total Fat: 3.24 g Total Fat: 0.28 g Total Fat: 2.97 g Protein: 32.1 g Protein: 24 g Protein: 23.6 g https://fdc.nal.usda.gov/f https://fdc.nal.usda.gov/ https://fdc.nal.usda.gov/ dc-app.html#/food-detail fdc-app.html#/food- fdc-app.html#/food- s/331960/nutrients details/175180/nutrients details/175158/nutrients 38 Functions of Triglycerides Concentrated source of energy (9 kcal/g) Main fuel source when resting or engaging in light physical activity The body readily converts excess calories from carbohydrate, lipids, protein, and alcohol into body fat Insulates and protects vital organs Maintains body temp Aids in the absorption of A, D, E, K Helps transport essential nutrients in the bloodstream 39  Hypertrophy – Increase in cell ______ Hyperplasia – Increase in cell ______ Weight gain  Fat droplet gets bigger Weight loss  Fat droplet gets smaller 40 Phospholipids Similar structure to triglycerides One FA is replaced with a phosphate 41 Phospholipids Considered amphiphilic/amphipathic Phosphate “head” Hydrophilic Fatty acid “tails” Hydrophobic If placed in water, phospholipids will form micelles 42 Phospholipids Two major roles: Cell membrane component Functions as an emulsifier Sources of phospholipids: Supplied by the diet Lecithin found in egg yolks, wheat germ, and peanuts Synthesized by the body 43 Emulsification Sterols Type of steroid Carbons arranged in multi-ringed structures Best known sterol is cholesterol Cholesterol is needed to make: Steroid hormones/sex hormones Testosterone and estrogen Adrenal hormones Aldosterone, cortisol, etc. Cell membranes Vitamin D Bile Found in foods of __________ origin or synthesized by the body 45 Side Note: Phytosterols Phytosterols = Plant stanols and sterols Cholesterol-like compounds Found naturally in a range of plant-based foods Unrefined plant oils (Vegetable, nut, and olive oil) Nuts, seeds, whole grains, legumes Fruits, vegetables Foods fortified with phytosterols Health benefits Interfere with the intestinal absorption of dietary cholesterol Facilitate the excretion of biliary cholesterol in the feces Numerous clinical trials have demonstrated that daily consumption of phytosterols from phytosterol-rich foods can significantly lower LDL cholesterol levels Intake of 2 g/day lowers serum LDL-cholesterol by 8%-10% Learn more here: https://www.nccih.nih.gov/health/providers/digest/high-cholesterol-and-natural-products-scien ce https://lpi.oregonstate.edu/mic/dietary-factors/phytochemicals/phytosterols 46 Recommended Fat Intake No RDA for adults AI established for infants AMDR: 20 to 35% of total kcal Omega-3 Adequate Intake Amount (As ALA) 19 to 50-year-old males: 1.6 g 19 to 50-year-old females: 1.1 g DGAs: Consume more unsaturated fats and limit saturated fat to less than 10% of total calories 47 Application Question: Using the AMDR AMDR = 20-35% of total kcal Percentage chosen should be specific to an individual’s needs Example: Individuals who are highly active need a greater percentage of calories from protein and carbohydrate, and a lower percentage of calories from fat. Example 2: Individuals who overconsume calories when their fat intake is low might benefit from consuming a higher percentage of fat. Practice Example: If an active individual needs to consume 3,500 kcal per day to maintain their weight, and they need 20% of kcal from fat, how many kcal of fat should they consume each day? 3,500 kcal x 0.2 = 700 kcal from fat 700 kcal from fat = 77.8 grams of fat The remaining calories should be divided up among carbohydrate and protein. Below are two examples. 50% of kcal could be carbohydrate, 30% of kcal could be protein. (20% + 50% + 30% = 100%) 60% of kcal could be carbohydrate, 20% of kcal could be protein. (20% + 60% + 30% = 100%) 48 FYI: How Has the American Diet Changed Over Time? https://flowingdata.com/2016/05/17/the- changing-american-diet/ Americans are consuming more kcal, cheese, refined grains, chicken, corn- derived sweeteners, vegetable oils Americans are eating 400+ more calories per day than in the 1970s Most of these extra calories come from fats and oils and refined grains. Check out the charts at this link: https://www.ers.usda.gov/data-products/fo od-availability-per-capita-data-system/inte ractive-charts-and-highlights/ Look at how added fats and oils and added sugars and sweeteners has changed over time Check out this video on how the https://www.pewresearch.org/short-reads/2016/12/13/whats-on-your-table-how-americas-diet-has- changed-over-the-decades/ American diet has changed over time: https://youtu.be/CwYV-P40-jI?feature=sha red – 1:36 49 Average Daily Calories Available Per Capita from the U.S. Food Supply, Adjusted for Spoilage and Other Waste Meat, Vegetab Added Added Eggs, Grains Dairy Fruit Total les Fat Sugar Nuts 2,168 1970 463 432 267 70 125 410 402 kcal 2,405 1990 453 573 260 85 126 461 446 kcal The data in this table are based on loss-adjusted food availability data from the United2,673 2008 482 625 257 86 122 641 459 kcal States Department of Agriculture (USDA). These data depict the availability of different foods per capita, adjusted for losses like spoilage and waste. By calculating these losses, the USDA data closely approximates the amount of food that makes its way from the farm into the average American stomach. 50 https://www.pewresearch.org/short-reads/2016/12/13/whats-on-your-table-how-americas-diet-has- changed-over-the-decades/ 51 Mediterranean Diet Up to 40% fat, mostly MUFAs and PUFAs Foods that are abundant: Olive oil, fruits, vegetables, whole grains, beans, nuts and seeds Average consumption of Olive Oil in Greece is 20L per person per year! Olive oil is used in place of other fats, like margarine and butter Diet emphasizes minimally processed, seasonally fresh, and locally produced foods Small to moderate amounts of cheese, yogurt, and fish Limited amounts of red meat Drink sufficient water Drink red wine in moderation Exercise 52  Source: https://oldwayspt.org/traditional-diets/mediterranean-diet Mediterranean Diet General principles: Eat lots of vegetables. Change the way you think about meat. If you eat meat, have smaller portions Enjoy some dairy. Eat Greek or plain yogurt and try smaller amounts of a variety of cheeses. Eat seafood twice a week. Cook a vegetarian meal one night a week. Build meals around beans, whole grains, and vegetables, and heighten the flavor with fragrant herbs and spices. Use healthy fats. Olive oil, nuts, seeds, olives, avocados Switch to whole grains. For dessert, consider fresh fruit. Mediterranean Diet Benefits Lower risk of disease Reduces the risk of heart disease, Type 2 diabetes, certain cancers, Parkinson’s disease, Rheumatoid Arthritis, dental disease, depression, and Alzheimer’s disease Increased longevity Reduces the risk of death from heart disease and cancer Lower blood pressure Resveratrol, found in red wine, and grape juice, lowers blood pressure by increasing nitric oxide levels Lower risk of becoming obese/overweight Lots of nutrient dense foods: fruits, vegetables, whole grains, satiating nuts and fats, etc. Improved brain function, eye health, and fertility So…why aren’t we recommending this diet more often in the U.S.? Fat Digestion Mouth Lingual lipase is produced VERY LITTLE fat is digested Stomach Gastric lipase Breaks triglycerides into monoglycerides, diglycerides, and free fatty acids Fat floats on watery stuff, so little fat is digested Small Intestine CCK triggers bile release Bile emulsifies fat Pancreatic lipase acts upon micelles 55 Fat Digestion Pancreatic lipase Digests triglycerides into monoglycerides and free fatty acids Phospholipase Breaks phospholipids into free fatty acids, glycerol and phosphoric acid Cholesterol esterase Digests cholesterol esters into cholesterol and free fatty acids Fat digestion is very rapid. Only a small portion (5%) of fat passes through the small intestine and is excreted 56 Fat Absorption Absorption occurs by the brush border of the absorptive cells. Carbon chain length of a fatty acid or monoglyceride determines whether it’s absorbed by the cardiovascular system or the lymphatic system Cardiovascular system: Most short-chain and medium-chain fatty acids Portal vein  Liver Lymphatic system: Long-chain fatty acids are re-esterified into triglycerides Fat-soluble vitamins, and dietary cholesterol 57 Transporting Lipids in the Blood Lipids are transported in blood as lipoproteins Chylomicrons Transport dietary fats VLDL - Very-Low-Density Lipoprotein IDL - Intermediate-Density Lipoprotein LDL - Low-Density Lipoprotein HDL - High-Density Lipoprotein 59 Lipoprotein Composition and Major Roles Chylomicron Primary component: Triglyceride Key role: Carries dietary fat from the SI to the cells VLDL Carries lipids from the liver to the cells Primary component: Triglyceride Key role: Produced by liver – Carries lipids from the liver to the cells LDL – The “Bad” cholesterol Arises from VLDL Primary component: Cholesterol Key role: Carries cholesterol made by the liver and from other sources to the cells HDL – The “Good” cholesterol Primary component: Protein Key role: Reverse Cholesterol Transport; Helps remove cholesterol from the cells and, in turn, excrete cholesterol from the body 60 Lipoprotein Composition and Major Roles Lipoprotein Primary Key Role Component Chylomicron Triglyceride Carries dietary fat from the small intestine to cells VLDL Triglyceride Carries lipids both taken up and made by the liver to cells LDL Cholesterol Carries cholesterol made by the liver and from other sources to cells HDL Protein Helps remove cholesterol from cells and, in turn, excrete cholesterol from the body  Lipoprotein Interactions Transporting Lipids Dietary lipids are transported using chylomicrons Chylomicrons enter the lymphatic system via lacteals and travel through the lymphatic system to the blood Lipoprotein Lipase (LPL) is an enzyme attached to the inside of most cell membranes. When activated, LPL pulls (hydrolyzes) triglycerides from the chylomicrons Free fatty acids are taken up by cells, repackaged into triglycerides, and used for energy or put into storage Chylomicrons decrease in size and eventually become a chylomicron remnant Liver produces VLDL and HDL VLDL  _____  _____ HDL – Reverse Cholesterol Transport 63 LDL Removal from the Blood Receptor Pathway of Cholesterol Update 1. LDL is removed from the blood by cells with LDL (B-100) receptors. 2. LDL is broken down to free cholesterol and protein 3. When the cell is “full” (i.e., when free cholesterol saturates the cell), the B-100 receptor is down- regulated 4. When LDL is not being taken into the cell, the concentration of LDL increases in the blood LDL can be oxidized (damaged) by free radicals  plaque Antioxidants can reduce oxidation 64 LDL Removal from the Blood Scavenger Pathway for Cholesterol Uptake Oxidized LDL is “scavenged” from the circulation by WBCs (Macrophages) Scavenger WBCs  Foam Cells  Fatty Streak  Advanced Plaque  Blockage/Occlusion Diets high in saturated fat, trans fat and cholesterol encourage this process HDL can pick up cholesterol and ensure its return to the liver for excretion HDL can prevent LDL from being oxidized Atherosclerosis – Condition characterized by plaque build up in the arteries Can be triggered by physical or chemical damage to the artery Hypertension Chronic hyperlipidemia Circulation of free radicals or reactive oxygen species Chronic hyperglycemia Homocysteinemia 65 HDLs Role in Removing LDL From the Blood High-Density Lipoprotein (HDL) Produced by the liver and intestine Roams the bloodstream, picking up cholesterol from dying cells or other sources Reverse Cholesterol Transport – HDL returns cholesterol to the liver for excretion Prevents LDL from floating around and being oxidized 66 Health Concerns Like most nutrients, some fat is good, too little can be bad, and too much can be bad Moderation is key! Inadequate Omega-3 intake Excessive Omega-3 intake Impair the immune system Increase the risk of bleeding Rancid Fats Contain peroxides and aldehydes and other cell-damaging compounds The double bonds in polyunsaturated fats are particularly susceptible to light, oxygen, and heat and are easily destroyed Manufacturers prevent rancidity by: Using hydrogenated oils Sealing foods in airtight packages Adding antioxidants or other additives Health Concerns Diets high in trans-fats Increase blood cholesterol levels, lower HDL, and increase inflammation Consumption linked to weight gain, Type 2 Diabetes, and cardiovascular disease Diets high in saturated fat Increase the risk of obesity, cancer, and cardiovascular disease Limit ultra-processed foods, fried foods, restaurant foods, and processed red meat 68 Health Concerns – Cardiovascular Disease Development of CVD usually starts with a damaged blood vessel Smoking, diabetes, hypertension, high blood sugars, high homocysteine levels, increased LDL levels, low HDL levels, viral and bacterial infections, blood-vessel inflammation, etc. Atherosclerotic plaque forms and thickens over time Result: Heart attack and stroke Risk factors “Non-Modifiable” Age, biological sex, race and genetics “Modifiable” – Can be changed Blood triglyceride and cholesterol levels (see next slide), blood pressure, smoking, physical inactivity, obesity, diabetes, and other diseases 69 Blood Lipid Levels Lipid Panel = Total Cholesterol, LDL, HDL, and Triglycerides Total Cholesterol 50 mg/dL >60 mg/dL = “Cardioprotective” Higher = Better Triglycerides